The present invention relates to an exercise machine, in particular the present invention relates to a load regulator for the weights pack of exercise machines.
As is known, exercise machines are used in many exercises for physical culture or muscle and/or joint rehabilitation.
Such machines consist of a fixed frame, a weights pack, a handle or grip bar, a chain or cable connecting the handle to the weights pack.
The weights pack consists of a plurality of individual weight units consisting of small bricks, usually parallelepipeds.
The weights slide along two rod-shaped guides which are part of the frame in a predetermined direction.
Due to gravity, the weights tend to apply a force towards the ground, opposed by the force applied by the user who, while exercising, counters the force of the weights by cyclically applying a force on the handle which is transmitted to the weights thanks to the tension applied by the cable or by the chain.
In this way, the user lifts the weights during the active step of the exercise.
It is known that most training programs, whether for body-building and therefore to increase muscle mass, or for post-traumatic rehabilitation, involve multiple repetitions of the same exercise, in each of them varying the load to be lifted, that is to say, the effort required of the muscle involved.
For this reason exercise machines must allow the simple, rapid selection and variation of the load at the end of each repetition.
The load is regulated by selecting a predetermined number of small bricks in the weights pack, based on the reaction required of them during the exercise.
In practice, suitable means are used to associate with the cable connected to the handle a number of small bricks predetermined according to the weight to be lifted.
There are prior art machines in which each small brick has a vertical central through-hole and a central through-hole horizontal to the ground.
Said holes are communicating holes and, when the small bricks are stacked on one another, the vertical holes form a channel which receives a rod-shaped bar.
The rod-shaped bar is connected at one end to the cable to which the handle is connected and has a plurality of holes along its longitudinal extension.
When the bar is completely inserted in the channel formed by the vertical holes in the small bricks, each hole in the bar is coaxial with a relative horizontal hole in a small brick.
The desired load is selected manually by inserting a locking pin through a horizontal hole in one of the small bricks and the corresponding hole at the same height in the rod-shaped bar.
In this way, all of the small bricks above the small brick in which the pin is inserted are locked and associated with the bar (and therefore with the cable and the handle).
Moving the pin into one of the small bricks below the selected small brick increases the weight to be lifted because it increases the number of small bricks associated with the bar. Vice versa, inserting the pin in one of the small bricks above the selected small brick reduces the weight to be lifted.
Said machines have the disadvantage of only allowing manual regulation of the load to be applied, greatly limiting their applications which would be possible if electronics were used.
There are machines in which the load of the weights can be regulated automatically using a load selector involving the use of means for coupling the weights to the rod-shaped bar which can adopt a locked position in which they engage on the bar the small brick with which they are associated, and a released position in which the small brick is not pulled together with the bar.
Said means are associated with a belt which can slide in a direction parallel with the bar, resulting in the relative locked or released condition.
Such machines have a certain construction complexity and the sliding belt associated with the coupling means is subject to rapid wear.